An excellent interactive website for mapping European discovery and exploration in America is: http://www.geoamericas.com/view_maps/standards_organization.asp#us_era_1  
By using this site, viewers may choose from the following maps:
Exploration (1431-1779)

• Voyages of Discovery: The Atlantic (1431-1616)

• European Exploration of The Americas (1513-1740).

By selecting the Flash Interactive button, the viewer may choose routes the different European countries took to the New World, as well as the routes taken by individual explorers in America.  These routes may be viewed separately in layers, or altogether.

A wonderful website for free clip art maps is  http://www.worldatlas.com/clipart.htm.  On this site teachers may copy and print maps.  These include outline maps of the world, the United States, individual continents, and states.

Using these two sites together students may complete their own exploration assignments.